1. Field of the Invention
The invention relates to an assembly with a coolant circuit for an internal combustion engine, wherein the internal combustion engine can be thermally coupled to at least one coolant circuit. The internal combustion engine can especially be the drive motor of a vehicle such as a railroad vehicle. In this case the internal combustion engine provides traction to the vehicle. The internal combustion engine is thermally coupled to at least one coolant circuit, which is in turn thermally coupled or at least capable of being temporarily thermally coupled to a latent heat accumulator via at least one heat exchanger. The invention particularly relates to the field of railroad vehicles, in which much more powerful internal combustion engines are typically used than in road vehicles. The railroad vehicle can in particular be a locomotive, e.g., a diesel-electric locomotive. Using the preheating for other vehicles such as ships, however, is also conceivable. The invention further relates to a method of preheating the internal combustion engine.
2. Description of Prior Art
To avoid a cold start of an internal combustion engine, the engine is usually preheated via the coolant circuit of the engine. To this end, use is made of preheating devices that usually generate heat for heating the coolant in the coolant circuit by burning the same fuel that is also used to operate the internal combustion engine. The heat is delivered to the internal combustion engine by circulation of the heated coolant. The use of preheaters leads to additional fuel consumption and additional exhaust emissions.
Another option for preheating the coolant consists in the use of latent heat accumulators. For example, the use of paraffin or saline solution accumulators is known for road vehicles. The latent heat accumulator medium paraffin has a temperature of ca. 100° C. with the accumulator in the fully charged state.
Such latent heat accumulators require a large construction volume in order to store the heat needed for the preheating. The weight of such accumulators is also considerable. A further disadvantage resides in the fact that the accumulators discharge very slowly, in other words the preheating process takes a considerable amount of time. The latent heat accumulator medium paraffin in particular has a low thermal conductivity. High-performance internal combustion engines therefore cannot be heated in a reasonable amount of time with prior art latent heat accumulators with reasonable construction volumes and weights.